id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux
8769 Slightly over-aggressive join promotion in SQL for ordering mtredinnick mtredinnick "Right now, we promote any table join used in the ordering portion to an outer join if it potentially contains NULL values (the corresponding Django field has `null=True`). There are some cases where this is unnecessary. If we already used that join in the filter statements and didn't make it an outer join at that point, it's because we are already filtering out the null values, so an inner join still won't lose any results in the ordering.
Thus, we should only promote joins for ordering if we needed to add that join for the ordering (this means `self.alias_refcount[...] == 1`, or something else that's easily detectable).
Noting this so I don't forget. Don't want to introduce new bugs at the moment and it's a bit of an edge case, so it can wait until post-1.0." Cleanup/optimization closed Database layer (models, ORM) master Normal fixed Accepted 0 0 0 0 0 0